Fluid control module for waste heat recovery systems

ABSTRACT

A fluid control module ( 200, 400 ) for a waste heat recovery system ( 100 ) with a working fluid is provided. The fluid control module comprises a module body ( 250, 430 ) at least partially enclosing a pump ( 220 ) and at least one valve ( 210, 230, 240, 410, 420 ), the module body having no dynamic seals to atmosphere.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Divisional Application of application Ser. No. 14/435,238,with a filing date of Apr. 13, 2015 entitled “FLUID CONTROL MODULE FORWASTE HEAT RECOVERY SYSTEMS,” which is a National Stage entry ofInternational Application No. PCT/GB13/52715, with an internationalfiling date of Oct. 17, 2013 entitled “FLUID CONTROL MODULE FOR WASTEHEAT RECOVERY SYSTEMS”, which claims priority of U.S. provisional patentapplication No. 61/714,964, filed Oct. 17, 2012 entitled “VEHICLE WASTEHEAT RECOVERY SYSTEM”, U.S. provisional patent application No.61/823,102 filed on May 14, 2013 entitled “BYPASS VALVE”, U.S.provisional patent application No. 61/828,260 filed on May 29, 2013entitled “VEHICLE WASTE HEAT RECOVERY SYSTEM”, U.S. provisional patentapplication No. 61/844,973 filed on Jul. 11, 2013 entitled “STATIC SEALFLUID CONTROL MODULE FOR WASTE HEAT RECOVERY SYSTEMS,” and U.S.provisional patent application No. 61/846,490 filed on Jul. 15, 2013entitled “FLOW SPLITTER”.

TECHNICAL FIELD

The embodiments described below relate to, fluid control modules, andmore particularly, to fluid control modules for waste heat recoverysystems.

BACKGROUND OF THE INVENTION

Internal combustion (IC) engines are used throughout the world andmainly for motor vehicles. IC engines account for one of the largestconsumers of petroleum products known. Due to the large amount ofpetroleum products consumed by IC engines and the gases exhausted fromIC engines, numerous regulatory agencies have implemented regulations orare in the process of implementing regulations that require minimumaverage fuel economy of vehicles as well as limit the amount ofpollutants that are exhausted from vehicles.

Earlier attempts at reducing vehicle emissions have centered on exhaustgas treatments. For example, earlier attempts have introduced reagentsinto the exhaust gas stream prior to the gas passing through a catalystin order to effect selective catalytic reduction (SCR) of the nitrogenoxides (NO_(x)) in the exhaust gases. Additionally, many vehicles nowinclude exhaust gas recirculation (EGR) systems to recirculate at leastsome of the exhaust gases. Although EGR reduces the harmful emissions ofvehicles, it also often reduces the vehicle's fuel economy.

The uses of SCR and EGR have been effective in reducing the emissionproblems in the exhaust stream, but have done little in improving thefuel economy and fuel consumption of vehicles. With the tighterregulations that are being implemented, many manufacturers have turnedtheir focus to increasing the fuel economy of IC engines. It isgenerally known that only about thirty to forty percent of the energyproduced by the fuel combustion of IC engines translates to mechanicalpower. Much of the remaining energy is lost in the form of heat.Therefore, one particular area of focus in the motor vehicle industryhas been to recover some of the heat that is generated by the IC engineusing a waste heat recovery system that converts heat into mechanicalenergy with, for example, a Rankine cycle.

While these prior art attempts have improved the vehicle's efficiency,they lack adequate control of the working fluid and the working fluid'stemperature. For example, U.S. Pat. No. 4,031,705 discloses a heatrecovery system that heats the working fluid using heat from the ICengine's exhaust and the IC engine's cooling circuit, i.e., the ICengine's radiator. Therefore, while the '705 patent does utilizemultiple heat sources, there is no way to adequately control where theheat is being drawn from. This can be problematic at times sinceinsufficient flow of working fluid to a heat source can reduce theoverall efficiency of the heat recovery system and/or result in wetsteam being fed to the expander.

Waste heat recovery systems may use a working fluid to recover the wasteheat from the engine. Some waste heat recovery system may use water. Insuch waste heat recovery systems, the water may be heated to steam usingan evaporator. Other fluids, which may be non-aqueous, and which mayinclude hydrocarbons such as ethanol or organofluorines such as Freon®,may also be used due to properties such as heat transfer, vapor pressureor freezing point (for example, a freezing point temperature lower thanthat of water). However such other fluids may combust when exposed to ahot metal surface such as an exhaust pipe on an engine or may berestricted by regulations when released to atmosphere. The fluids mayalso decompose when exposed to atmosphere. Such fluids may also be moreprone to leaking past dynamic seals, i.e. seals that employ abuttingsurfaces that are configured to move relative to one another, due to,for example, lower fluid viscosity or limited lubrication for thedynamic seals.

Many waste heat recovery systems employ fluid control modules to controlthe flow of the working fluid through the waste heat recovery systems.For example, the fluid control modules may employ valves that regulatethe working fluid flow to expanders in the waste heat recovery system.Such valves may utilize dynamic seals with working fluid on one side ofthe dynamic seal and atmosphere on the other side of the dynamic seal.These may be referred to as atmospheric dynamic seals. Sometimes thedynamic seals fail unexpectedly causing the working fluid to leak toatmosphere or onto a hot engine surface. Static seals may not be asprone to failure as dynamic seals.

Accordingly, there is a need for a static seal fluid control module forwaste heat recovery systems. There is also a need for waste heatrecovery systems with fluid and vapor control modules that do not haveatmospheric dynamic seals.

SUMMARY OF THE INVENTION

A fluid control module for a waste heat recovery system with a workingfluid is provided according to an embodiment. The fluid control modulecomprises a module body at least partially enclosing a pump and at leastone valve, the module body having no dynamic seals to atmosphere.

A method of forming a fluid control module for a waste heat recoverysystem with a working fluid is provided according to an embodiment. Themethod comprises forming and at least partially enclosing a pump and atleast one valve with a module body without forming a dynamic seal toatmosphere.

A method of operating a fluid control module is provided according to anembodiment. The method comprises receiving a working fluid at an inletof the fluid control module, and providing the working fluid to one ormore evaporators and to a pilot valve actuator on a bypass valve withoutcontaining the working fluid with an atmospheric dynamic seal.

ASPECTS

According to an aspect, a fluid control module for a waste heat recoverysystem with a working fluid is provided. The fluid control modulecomprises a module body at least partially enclosing a pump and at leastone valve, the module body having no dynamic seals to atmosphere.

Preferably, the pump and the at least one valve are adapted to besubstantially immersed in the working fluid.

Preferably, the pump is adapted to be driven electrically.

Preferably, the pump comprises a moving element, in particular a rotor,that is adapted to be immersed in the working fluid.

Preferably, the pump comprises one or more bearings adapted to beimmersed in the working fluid.

Preferably, the pump comprises a stator at least partially enclosed bythe module body.

Preferably, the at least one valve comprises an electromagnetic actuatorcomprising a core, the core being adapted to be immersed in the workingfluid.

Preferably, the at least one valve comprises a return spring adapted toplace the at least one valve in a zero position state when the at leastone valve is not actuated.

Preferably, the return spring is adapted to be immersed in the workingfluid.

Preferably, the at least one valve includes a solenoid at leastpartially enclosed by the module body.

Preferably, the fluid control module comprises a first liquid controlvalve configured to selectively provide a fluid communication pathbetween a fluid supply and a first evaporator port and a second liquidcontrol valve adapted to selectively provide a fluid communication pathbetween the fluid supply and a second evaporator port.

Preferably, the fluid control module comprises a proportional flowcontrol valve that includes a proportional stem that is adapted toproportionally regulate a flow of the working fluid between a firstevaporator port and a second evaporator port.

Preferably, the fluid control module comprises a return spring assemblyadapted to return the proportional flow control valve to a zero positionstate.

Preferably, the at least one valve includes a stem adapted to regulatethe working fluid flow to a pilot valve actuator on a bypass valve.

Preferably, the at least one valve includes a stem adapted to regulate aflow of the working fluid to a bypass circuit to de-superheat theworking fluid.

Preferably, the at least one valve includes a stem adapted to regulatethe working fluid flow to a pilot valve actuator on a bypass valve andto a bypass circuit to de-superheat the working fluid.

Preferably, the fluid control module comprises a power line that iscoupled to the pump or the at least one valve wherein the power line isat least partially enclosed by the module body.

Preferably, the fluid control module comprises a pump return thatreturns fluid from the at least one valve to the pump.

According to an aspect, a method of forming a fluid control module for awaste heat recovery system with a working fluid is provided. The methodcomprises forming and at least partially enclosing a pump and at leastone valve with a module body without forming a dynamic seal toatmosphere.

Preferably, the method further comprises the step of substantiallyimmersing the pump and the at least one valve in the working fluid.

Preferably, the method further comprises the step of forming andimmersing a rotor in the working fluid.

Preferably, the method further comprises the step of forming andimmersing one or more bearings in the working fluid.

Preferably, the method further comprises the step of forming and atleast partially enclosing a stator in the module body.

Preferably, the method further comprises the step of forming andimmersing a core in the working fluid.

Preferably, the method further comprises the step of forming andadapting a return spring to place the at least one valve in a zeroposition state when the at least one valve loses power.

Preferably, the method further comprises the step of immersing thereturn spring in the working fluid.

Preferably, the method further comprises the step of at least partiallyenclosing a solenoid with the module body.

Preferably, the method further comprises the step of forming aproportional flow control valve.

Preferably, the method further comprises the step of forming andadapting a proportional stem to proportionally regulate a working fluidflow between a first evaporator port and a second evaporator port.

Preferably, the method further comprises the step of forming andadapting a return spring assembly to return the proportional controlvalve to a zero position state.

Preferably, the method further comprises the step of forming a stemadapted to regulate the working fluid flow to a pilot valve actuator ona bypass valve.

Preferably, the method further comprises the step of forming a stem toregulate the working fluid flow to a bypass circuit to de-superheat theworking fluid.

Preferably, the method further comprises the step of forming a stem toregulate the working fluid flow to a pilot valve actuator on a bypassvalve and to a vapor control module to de-superheat the working fluid.

Preferably, the method further comprises the step of forming andcoupling a power line to the pump or the at least one valve and at leastpartially enclosing the power line with the module body.

Preferably, the method further comprises the step of forming a pumpreturn that returns fluid from the one or more valves to the pump.

According to an aspect, a method of operating a fluid control module isprovided. The method comprises receiving a working fluid at an inlet ofthe fluid control module, and providing the working fluid to one or moreevaporators and to a pilot valve actuator on a bypass valve withoutcontaining the working fluid with an atmospheric dynamic seal.

Preferably, the method further comprises the step of providing theworking fluid to a bypass circuit without containing the working fluidwith the atmospheric dynamic seal.

Preferably, the method further comprises the step of providing theworking fluid to a venturi that forms a portion of the bypass circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic of a waste heat recovery system according to anembodiment.

FIG. 2 shows a cross-sectional view of a valve module according to anembodiment.

FIG. 3 is a detail view of FIG. 2.

FIG. 4 shows a first fluid control module according to an embodiment.

FIG. 5 shows an enlarged view of the proportional flow control valveshown in FIG. 4.

FIG. 6 shows a second fluid control module according to an embodiment.

FIG. 7 shows a simplified schematic of a fluid control module schematicaccording to an embodiment.

FIG. 8 shows another embodiment of a flow splitter.

FIGS. 9A and B are perspective and cross-sectional views of a furtherembodiment of a flow splitter;

FIG. 9C is a detail view of FIG. 9B.

FIG. 9D is a detail view of FIG. 9C.

DETAILED DESCRIPTION OF THE INVENTION

The above figures and the following description depict specific examplesto teach those skilled in the art how to make and use the best mode ofembodiments of a static seal fluid control module in a waste heatrecovery system and a waste heat recovery system. For the purpose ofteaching inventive principles, some conventional aspects have beensimplified or omitted. Those skilled in the art will appreciatevariations from these examples that fall within the scope of the presentdescription.

Those skilled in the art will appreciate that the features describedbelow can be combined in various ways to form multiple variations of thestatic seal fluid control module and the waste heat recovery system. Asa result, the embodiments described below are not limited to thespecific examples described below, but only by the claims and theirequivalents.

FIG. 1 shows a schematic of a waste heat recovery system 100 for anengine 101 according to an embodiment. The waste heat recovery system100 may be implemented for an engine 101 mounted on a motor vehicle (notshown) to drive that vehicle, for example. Therefore, the engine 101 maycomprise an IC engine, in particular a reciprocating piston engine. Thevehicle may be an on-road truck, the operation of which is set out inthe standard ‘highway cycle’ or World Harmonized Test Cycle (WHTC). Sucha truck engine may particularly be powered by diesel or natural gas.According to an embodiment, the waste heat recovery system 100 caninclude a fluid control module 102 and a vapor control module 103.According to an embodiment, the waste heat recovery system 100 includesa fluid supply 104. The fluid supply 104 may include a fluid, such aswater, an organofluorine such as Freon®, or a hydrocarbon such asethanol, or the like as the working fluid. The particular fluid used mayvary from one application to another. For example, the fluid may be thefuel used by the engine 101. A high-pressure fluid pump 105 is in fluidcommunication with an outlet of the fluid supply 104. The high-pressurefluid pump 105 may be driven by the engine 101, e.g. from the enginecrankshaft in the case of a reciprocating piston engine, or may bedriven by a separate electric motor, for example. In some embodiments,the high-pressure fluid pump 105 may raise the pressure of the fluid toa threshold pressure of approximately 40 bar (580 psi) from thereservoir pressure, which is typically at atmospheric pressure. However,other threshold pressures are certainly possible and the particularexample pressure should in no way limit the scope of the presentembodiment.

A main system controller and electrical leads to the controllablecomponents of the waste heat recovery system 100 are not shown in FIG. 1to reduce the complexity of the figure. However, those skilled in theart will readily appreciate suitable electronics that may be used tocontrol the waste heat recovery system 100. For example, the main systemcontroller may comprise a portion of the vehicle's main electronics. Theelectronics can control the various valves that are described furtherbelow based on temperature and pressure measurements of the system, forexample.

According to an embodiment, the fluid control module 102 can include apressure control valve 110 and a system drain valve 113. In theembodiment shown, the system drain valve 113 comprises a normally opensolenoid actuated valve. However, other types of valves can certainly beused. When de-actuated, the system drain valve 113 can drain the fluidback to the fluid supply 104. This may occur when the vehicle is turnedoff, when fluid is not desired to be run through the waste heat recoverysystem 100, or in the event of an emergency, for example. The fluidcontrol module 102 may further comprise a valve module 114.

Those skilled in the art can readily recognize that while thehigh-pressure fluid pump 105 may deliver a varying pressure that ishigher than the desired threshold pressure to the fluid control module102, the pressure control valve 110 can ensure that the valve module 114receives a relatively constant input pressure. According to anembodiment, the valve module 114 can include two or more fluid controlvalves 118, 119. In one embodiment, the two or more fluid control valves118, 119 can be in the form of proportional valves. According to anembodiment, the valve module 114 can selectively provide a fluidcommunication path between the fluid supply 104 and one or more of thetwo or more evaporators 120, 121.

According to an embodiment, the two or more evaporators 120, 121 mayreceive waste heat generated by the engine 101. For example, in oneembodiment, the first evaporator 120 uses the heat from the engine's EGRwhile the second evaporator 121 uses the heat from the engine's exhaust.A third evaporator, not shown, may receive heat from a third source,such as the charge air circuit. According to an embodiment, the two ormore evaporators 120, 121 may be at different temperatures. Therefore,the valve module 114 can control the actuation of the valves 118, 119based on a measured temperature at the inlet of the vapor control module103, thereby selecting the proportion of the fluid flow from the pumpthat passes through the first evaporator and the proportion of the fluidflow from the pump that passes through the second evaporator. Inaddition to the temperature measured at the inlet of the vapor controlmodule 103, pressure sensors 122, 123 may be provided at the outlets116, 117 of the valve module 114. It should be appreciated however, thatthe pressure sensors 122, 123 are optional and may be omitted.

Because of the elevated temperature of the two or more evaporators 120,121, the liquid leaving the valve module 114 can become a superheatedvapor. For example, in one embodiment, the valve module 114 can controlthe two or more valves 118, 119 such that the superheated vapor enteringthe vapor control module 103 is at approximately 400.degree. C.(752.degree. F.) and 40 bar (580 psi). However, those skilled in the artcan readily appreciate that these values may vary based on theparticular application and should in no way limit the scope of thepresent embodiment.

As can be seen from FIG. 1, the vapor control module 103 can include abypass valve 128. In the embodiment shown, the bypass valve 128comprises a spring biased, fluid actuated 3/2-way valve. Alternatively,the bypass valve 128 may comprise a proportional flow control valve. Inthe embodiment shown, the bypass valve 128 can selectively provide afluid communication path between the two or more evaporators 120, 121and either an expander 129, which may be a piston expander, or a bypasscircuit 130. According to an embodiment, the bypass valve 128 can bebiased towards a first position where a fluid communication path isprovided between the two or more evaporators 120, 121 and the bypasscircuit 130. Therefore, in a default position, the expander 129 isbypassed and waste heat from the engine 101 is not recovered. Instead,the vapor flows directly to a condenser 134. According to an embodiment,in the first position, the fluid from the two or more evaporators 120,121 flows through a needle valve 131 and a venturi 132. In someembodiments, the venturi 132 can receive an optional fluid supply fromthe fluid control module 102 via a de-superheat control valve 133. Thede-superheat control valve 133 is in fluid communication with thepressurized fluid leaving the high-pressure fluid pump 105. Therefore,injection of cooling fluid into the bypass circuit 130 can cool thesuperheated vapor to de-superheat the fluid. De-superheating the fluidcan provide a substantially cooler fluid to the condenser 134, whichreduces the thermal shock to the condenser 134.

Additionally or alternatively, a flow control valve 142 may regulate theflow of the fluid from the de-superheat control valve 133 to the venturi132. The flow control valve 142 may control the flow based on parametersin the waste heat recovery system 100 and/or the engine 101. Forexample, temperature gauges 124, 144 may provide a temperature of fluidflowing to the condenser 134. The flow control valve 142 may control theflow of the cooling fluid to the venturi 132 based on the temperature ofthe fluid flowing towards the condenser 134. The flow control valve 142may also control the flow based on the engine's 101 power output. Forexample, the flow control valve 142 may increase the flow of coolingfluid to the vapor flowing to the condenser 134 when the engine's 101power output drops due to the operator releasing the gas pedal. Thecooling fluid may also de-superheat the vapor when the vapor controlmodule 103 diverts the superheated fluid flow from the expander 129 tothe condenser 134.

According to an embodiment, actuating a pilot supply valve 137 and anexhaust valve 138 can actuate the bypass valve 128 from the firstposition to a second position via a pilot valve actuator 139. The pilotsupply valve 137 can supply fluid from the fluid supply 104 to a pilotvalve actuator 139 via a fluid line 140. Therefore, the pilot supplyvalve 137 can selectively provide a fluid communication path between thefluid supply 104 and the pilot valve actuator 139. The fluid supplied tothe pilot valve actuator 139 can actuate the bypass valve 128 to asecond position. According to an embodiment, in the second position, thebypass valve 128 can selectively provide a fluid communication pathbetween the two or more evaporators 120, 121 and the expander 129.

The superheated vapor flows to the expander 129 where it reduces inenthalpy while expanding as is generally known in the art. Therefore,the expander 129 can convert at least some of the energy of thesuperheated vapor to mechanical work. The expander 129 can comprise avariety of well-known devices, such as a turbine, a piston, a vaporengine, such as a rotary vane type vapor engine, etc. The particulartype of expander 129 utilized is not important for purposes of thepresent description and should in no way limit the scope of the claimsthat follow. For purposes of the present application, the importantaspect of the expander 129 is that it can convert the energy of thesuperheated vapor into useful mechanical energy. In some embodimentswhere the expander 129 comprises a vapor engine, for example, theexpander 129 can be coupled to the crankshaft or other suitablecomponent of the engine 101 in order to add power to the engine 101 asis generally known in the art. An example would be an overrunning clutchassembly, which can transfer power from the vapor engine to the engine101, but not the reverse. According to an embodiment, the fluid canleave the expander 129 and travel to the condenser 134 via a fluid line135 where the fluid is cooled and delivered back to the fluid supply104.

With a basic description of the overall waste heat recovery system 100,attention is now drawn to the seals. The fluid control module 102 andthe vapor control module 103 may have seals exposed to atmosphere thatare only static seals. That is, there may not be any dynamic sealsexposed to atmosphere or atmospheric dynamic seals. The term,“atmospheric dynamic seals,” is not necessarily limited to dynamic sealswith ambient air at atmospheric pressures on one side of the seal. Forexample, the atmospheric dynamic seals may refer to seals potentiallyexposed to pressures greater than and less than the standard earthatmosphere. Also, the term ‘atmospheric’ may include any ambientenvironment that surrounds the waste heat recovery system. Dynamic sealsare seals that move relative to a sealing surface.

The waste heat recovery system 100 may employ fluid and vapor controlmodules that have no atmospheric dynamic seals. Instead, the dynamicseals may be exposed to, for example, the working fluid on both sides ofthe seal. For example, the vapor control module 103 may have a dynamicseal with superheated working fluid on one side and pressurized fluid onthe other side. The pressurized fluid may be provided by the fluidcontrol module 102 via the pilot supply valve 137. Accordingly, thewaste heat recovery system 100 may have fluid and vapor control modulesthat do not employ atmospheric dynamic seals. Embodiments of the staticseal fluid control modules are described in more detail in the followingwith reference to FIGS. 2-5.

Valve Module

FIG. 2 shows a cross-sectional view of a valve module 114 according toan embodiment. According to an embodiment, the valve module 114comprises a housing 1214, which may be separated into multiple parts asshown. According to the embodiment shown, the valve module 114 comprisesthe two liquid control valves 118, 119. According to an embodiment, thefirst liquid control valve 118 comprises a normally opened valve whilethe second liquid control valve 119 comprises a normally closed valve.

According to an embodiment, the first liquid control valve 118 comprisesa biasing member 1244, which biases a valve member 1245 away from avalve seat 1246. In the embodiment shown, the valve member 1245 alsocomprises a needle. A linear stepper motor 1247 or some other actuatorcan be provided to actuate the valve member 1245 towards the valve seat1246. According to an embodiment, the second liquid control valve 119comprises a biasing member 1240, which biases a valve member 1241towards a valve seat 1242. In the embodiment shown, the valve member1241 comprises a movable needle. The needle is tapered, which allows forproportional control of the fluid. A linear stepper motor 1243 or someother actuator can be provided to actuate the valve member 1241 awayfrom the valve seat 1242.

Although other types of actuators are certainly possible, linear steppermotors are generally known and can provide relatively accuratepositional control, which can allow proportional fluid control.Therefore linear stepper motors are particularly suitable for thepresent application.

It should be appreciated that while the liquid control valves 118, 119are described as comprising normally open and normally closed valves,the reverse could also occur. Alternatively, both of the valves 118, 119may be biased towards the same direction, i.e., both normally closed orboth normally open. Therefore, the particular configuration shown shouldin no way limit the scope of the present embodiment.

As shown in FIG. 2, the valve member 1241 can selectively provide afluid communication path between the inlet 115 and the outlet 117.Similarly, the valve member 1245 can selectively provide a fluidcommunication path between the inlet 115 and the outlet 116.

FIG. 3 shows an enlarged view of a portion of the valve 118 of FIG. 2according to an embodiment. Although the discussion relates to the valve118, it should be appreciated that other than the position of thebiasing members 1240, 1244, the valves operate substantially similarly.Therefore, the features discussed in relation to FIG. 3 can easily beapplied for the valve 119. As mentioned above, the waste heat recoverysystem 100 can operate under relatively high pressures (40 bar, 580 psi)and elevated temperatures. Therefore, the valves 118, 119 includecertain features that allow for such high pressures without failingprematurely. According to an embodiment, the valve seat 1246 cancomprise one or more bushings 346, which forms a fluid tight seal withthe valve module housing 1214. In the embodiment shown, a one-piecebushing 346 is provided; however, it should be appreciated that inalternative embodiments, the bushing 346 can be separated into multiplecomponents. The bushing 346 can form a fluid tight seal with the housing1214 via one or more sealing members 360, 361, 362. According to anembodiment, the bushing 346 can comprise a lower bore 347 and an upperbore 348. The valve member 1245 can slide within the lower and upperbores 347, 348 and can form a substantially fluid-tight seal. The sealbetween the valve member 1245 and the bores 347, 348 is due to theextremely tight tolerances between the components. Although theparticular dimensions may vary, in one embodiment, the differencebetween the inner radius of the bores 347, 348 and the outer radius ofthe valve member 1245 is between 5-10 microns (0.0002-0.0004 inches).For example, in one embodiment, the valve member 1245 comprises amaximum diameter, D.sub.1 of 2.0000 mm while the bores 347, 348 comprisean inner diameter of 2.0005 mm.

According to the embodiment shown, the valve member 1245 is in theclosed position wherein a portion of the valve member 1245 having amaximum diameter, D.sub.1 is sealed against the lower bore 347.Consequently, because of the tight sealing tolerance, a substantiallyfluid-tight seal is formed and most of the fluid is prevented fromflowing from the inlet 115 towards the outlet 116. However, as the valvemember 1245 is raised upwards (according to the orientation shown), thediameter of the valve member 1245 proximate the lower bore 347 decreasesto a minimum diameter, D.sub.2. As the diameter proximate the lower bore347 decreases, a space between the valve member 1245 and the lower bore347 is created to allow fluid to flow from the inlet 115 towards theoutlet 116. As can be appreciated, when the entire valve member 1245 isabove the lower bore 347, a maximum flow can be achieved. However, whileat least a portion of the valve member 1245 remains within a portion ofthe lower bore 347, proportional flow control can be achieved.

Although the tight tolerances between the bores 347, 348 and the valvemember 1245 are designed to provide a substantially fluid tight sealing,at higher pressures, some fluid is likely to leak past the substantiallyfluid-tight seal and thus, the valve module 114 includes a fluid returnport 350. The fluid return port 350 is positioned between the bushing346 and the biasing member 1244. The fluid return port 350 may be influid communication with the fluid supply 104, for example. While themaximum diameter D.sub.1 of the valve member 1245 maintains asubstantially fluid tight seal with the upper bore 348, in the eventthat fluid flows past the valve member/upper bore interface, the fluidwill simply be diverted back to the fluid supply 104 at a substantiallyreduced pressure via the fluid return port 350. A sealing member 351 canalso prevent fluid from flowing past the fluid return port 350 towardsthe biasing member 1244. According to an embodiment, the sealing member351 may comprise an elastomer sealing member with a lip that engages thevalve member 245, the substantially reduced pressure in port 350reducing friction and wear of the seal. However, other types of sealingmembers may be used.

The features described above for the valve module 114 allow for preciseand proportional control of high-pressure liquids

First Static Seal Fluid Control Module

FIG. 4 shows a first static seal fluid control module 200 according toan embodiment. The first static seal fluid control module 200 maycorrespond to the fluid control module 102 shown in FIG. 1. The firststatic fluid control module 200 may not have any atmospheric dynamicseals. As shown, the first static seal fluid control module 200 mayinclude a proportional flow control valve 210, an electrically-poweredpump 220, a de-superheat control valve 230, and a bypass control valve240 enclosed by a module body 250. The module body 250 may include apower line 260 that is coupled to conductors 262 a-d. The power line 260and the conductors 262 a-d may provide electrical power to theproportional flow control valve 210, the pump 220, the de-superheatcontrol valve 230, and the bypass control valve 240 so the first staticseal fluid control module 200 may regulate the flow of the working fluidin the waste heat recovery system 100. The module body 250 may becomprised of stainless steel selected for corrosion and heat resistantproperties although any suitable material may be employed. Magneticproperties may also be considered. The proportional flow control valve210 may be adapted to proportionally regulate the working fluid betweenthe evaporators 120, 121. The proportional flow control valve 210 isdescribed in more detail in the following with reference to FIG. 5.

Still referring to FIG. 4, the pump 220 may include a pump rotor 222that is movably (e.g., rotatably) coupled to the module body 250 viarotor bearings 224 a,b. The pump rotor 222 may be comprised of aferromagnetic material. The pump rotor 222 may also be coupled to animpeller 226 that is in an impeller chamber 252. The pump rotor 222 maybe magnetically coupled to a pump stator 228. The pump stator 228 may becoupled to the power line 260 via the conductor 262 a. The pump rotor222, the rotor bearings 224 a,b, and the impeller 226 may be comprisedof material that is selected for magnetic properties as well ascompatibility with the working fluid. The pump stator 228 may beenclosed by the module body 250. The pump stator 228 may be comprised ofa conductor such as copper configured to generate a magnetic field withcurrent supplied by the power line 260.

The de-superheat control valve 230 may include a valve core 232 that isslidably coupled to the module body 250. A return spring 234 may bedisposed between the valve core 232 and the module body 250 to provide abiasing force. As shown, the biasing force presses the valve core 232 toplace the de-superheat control valve 230 in an open or zero positionstate. The valve core 232 may be magnetically coupled to a solenoid 236.The valve core 232 may include a stem 232 a that is partially disposedin a de-superheat control chamber 253. The solenoid 236 may be coupledto the power line 260 via the conductor 262 c. The de-superheat controlchamber 253 may be in fluid communication with a de-superheat port 238.

The bypass control valve 240 may include a valve core 242 that isslidably coupled to the module body 250. The valve core 242 may becomprised of a ferromagnetic material selected for materialcompatibility with the working fluid. A return spring 244 may bedisposed between the valve core 232 and the module body 250 to provide abiasing force. As shown, the biasing force presses the valve core 242 toplace the bypass control valve 240 in an open or zero position state asshown. A solenoid 246 may be magnetically coupled to the valve core 242.The return spring 244 may also be disposed in a bypass control chamber254. The bypass control chamber 254 may be in fluid communication with abypass pilot port 248. The valve core 242 may include a stem 242 a thatis adapted to regulate the working fluid flow through the bypass pilotport 248.

As shown in FIG. 4, the module body 250 may include chambers are that influid communication with each other. For example, the impeller chamber252 may be in fluid communication with the de-superheat control chamber253 and the bypass control chamber 254. The module body 250 may alsoinclude inlets and outlets that are in fluid communication with otherparts of the waste heat recovery system 100. For example, evaporatorports 251 a,b may be in fluid communication with the evaporators 120,121. In addition to being in fluid communication with the bypass pilotport 248, the bypass control chamber 254 may be in fluid communicationwith the de-superheat port 238 and the impeller chamber 252. An inlet252 a may be in fluid communication with the impeller chamber 252 andmay provide working fluid to the proportional flow control valve 210.Exemplary flows through the module body 250 are shown by arrows at theinlet 252 a and the ports 238, 248.

In an embodiment, the module body 250 may enclose the proportional flowcontrol valve 210, the pump 220, the de-superheat control valve 230, andthe bypass control valve 240. Components in the module body 250 may beimmersed in the working fluid. For example, the pump rotor 222, thevalve core 232, and the valve core 242 may be immersed in the workingfluid. There may also be no atmospheric dynamic seals between, forexample, the pump rotor 222 or the valve cores 232, 242 and the modulebody 250. Accordingly, the working fluid may be retained by the modulebody 250 and static seals at the evaporator ports 251 a,b, thede-superheat port 238, and the bypass pilot port 248. Although retainedby static seals, the working fluid flow through the first static sealfluid control module 200 may be regulated, for example, by theproportional flow control valve 210, which is described in more detailin the following.

FIG. 5 shows an enlarged view of the proportional flow control valve 210shown in FIG. 4. The proportional flow control valve 210 may include aproportional stem 212 that is coupled to a motor 214. The proportionalstem 212 may also be coupled to a return spring assembly 216. Theproportional stem 212 may be slidably coupled to the module body 250. Aportion of the proportional stem 212 and the motor 214 may be disposedin a motor chamber 251 c. A portion of the proportional stem 212 and thereturn spring assembly 216 may be disposed in a spring chamber 251 d.The motor chamber 251 c and the spring chamber 251 d may be fluidlycoupled with each other via a conduit 251 e. A portion of theproportional stem 212 may also be disposed in a displacement chamber 251f.

The proportional stem 212 may include a flow control profile 212 a thatmay proportionally regulate the flow of the working fluid through thefirst evaporator port 251 a and the second evaporator port 251 b. Theflow profile can be adapted to have a constant flow capacity that isindependent of the position of the valve stem and may be viewed ascomprising first and second valve members 270 a, 270 b adapted toregulate a flow of the working fluid between the inlet port and thefirst evaporator port 251 a and the second evaporator port 251 brespectively, the first and second valve members being arrangedsymmetrically on the stem.

Inner stem bushings 212 b,c on the proportional stem 212 may guide themovement of the proportional stem 212. The proportional stem 212 mayalso include stem threads 212 d slidably coupled to the motor 214. Thestem threads 212 d may be adapted to move the proportional stem 212 in alinear direction in the module body 250 as the rotor 214 a rotates. Anassembly rod 212 e, a stem bushing 212 f, and a shoulder 212 g on theproportional stem 212 may press against portions of the return springassembly 216 as will be discussed in more detail in the following.

The motor 214 may include a rotor 214 a that is movably (e.g.,rotatably) coupled to the module body 250 via a bearing 214 b. A stator214 d may be magnetically coupled to the rotor 214 a. The rotor 214 amay be coupled to the proportional stem 212 via a rotor hub 214 c. Thestator 214 d may be electrically coupled to the conductor 262 b. Thestator 214 d may be adapted to use electrical power provided by theconductor 262 b to rotate the rotor 214 a via the magnetic coupling.

The return spring assembly 216 may include an outer spring retainer 216a, an inner spring retainer 216 b, and a return spring 216 c. The returnspring 216 c may press the outer spring retainer 216 a and the innerspring retainer 216 b against an inner surface of the spring chamber 251d and the stem bushing 212 f and the shoulder 212 g. As shown in FIG. 5,the return spring 216 c is pressing the outer and inner spring retainers216 a, b against the inner surface of the spring chamber 251 d. Theproportional stem 212 is shown in a zero position. In the zero position,the working fluid flow ratio between the first evaporator port 251 a andthe second evaporator port 251 b may be about 1. That is, the workingfluid flow rate through the first evaporator port 251 a and the secondevaporator port 251 b may be the same. Alternately, the zero or defaultposition may be configured to provide any flow ratio needed to satisfythe application. For example: alternate default flow ratios can beachieved by simply moving the relative position of the profile 212 a ofthe stem 212 in relation to the zero or default position of returnspring assembly 216.

In operation, the proportional stem 212 may move linearly in the modulebody 250. The stator 214 d may use electrical power to rotate the rotor214 a which moves the proportional stem 212 via the stem threads 212 d.As the proportional stem 212 moves linearly in the module body 250, aflow rate ratio of the working fluid through the first evaporator port251 a and the second evaporator port 251 b changes due to the flowcontrol profile 212 a. For example, when the proportional stem 212 isdisplaced towards the displacement chamber 251 f, the working fluid flowrate through the second evaporator port 251 b is greater than theworking fluid flow rate through the first evaporator port 251 a. Theratio may be proportional to the amount the proportional stem 212 isdisplaced from the zero position.

When the conductor 262 d does not have power, the return spring assembly216 may move the proportional stem 212 to the zero position. Forexample, if the proportional stem 212 is fully displaced towards thedisplacement chamber 251 f by the motor 214, the return spring 216 c maypress the proportional stem 212 towards the motor 214 when the motor 214loses power. The proportional stem 212 may therefore move to the zero ordefault position shown in FIG. 5.

The displacement dimensions of the spring chamber 251 d and the rotorhub 214 c may be selected to prevent the proportional stem 212 fromblocking the fluid flow through the proportional flow control valve 210.For example, a length of the displacement chamber 251 f may besufficient to allow the proportional stem 212 to fully compress thereturn spring 216 c and limit flow through the first evaporator port 251a and allow fluid to flow from an inlet 251 g to the second evaporatorport 251 b. An exemplary fluid flow is shown by arrows at the ports 251a,b,g. Other dimensions may be selected to prevent proportional stem 212from blocking the working fluid flow through the proportional flowcontrol valve. For example, the stem threads 212 d may be dimensioned toreach the bottom of the rotor hub 214 c to prevent the proportional stem212 from moving further towards the motor 214. Additionally oralternatively, a shoulder on the proportional stem 212 may also reachthe rotor 214 a, thereby preventing the proportional stem 212 fromfurther moving towards the motor 214.

Accordingly, when the first static seal fluid control module 200 losespower, proportional stem 212 may return to the zero position where theworking fluid may flow through the proportional flow control valve 210at its predetermined default ratio. The working fluid may thereforealways flow through the proportional flow control valve 210. Theproportional flow control valve 210 may be fail-safe in that the workingfluid is not prevented from flowing through the waste heat recoverysystem 100 by the proportional flow control valve 210. As a result,pressure may not build up in, for example, the evaporators 120, 121 tocause a rupture in the waste heat recovery system 100.

In the event of a catastrophic failure in the proportional flow controlvalve 210, the working fluid may continue to flow through theproportional flow control valve 210. For example, if the return spring216 c were to break or seize in the spring chamber 251 d, theproportional stem 212 may not be pressed towards the zero position.However, due to, for example, the displacement dimensions of the springchamber 251 d and the rotor hub 214 c not allowing the proportional stem212 to block the fluid flow. In such a failure mode, the working fluidmay still flow through the proportional flow control valve 210 therebypreventing an undesirably high pressure in the waste heat recoverysystem 100. Other embodiments that provide the same benefits may beprovided as will be described in the following with reference to FIGS. 4and 5.

Second Static Seal Fluid Control Module

FIG. 6 shows a second static seal fluid control module 400 according toan embodiment. The second static seal fluid control module 400 issimilar to the first static seal fluid control module 200. The secondstatic seal fluid control module 400 includes a proportional flowcontrol valve 410 and an integrated control valve 420 in a module body430. The second static seal fluid control module 400 also includes thepump 220 described in the foregoing with reference to FIG. 4. Similar tothe module body 250, the module body 430 may be comprised of stainlesssteel. The proportional flow control valve 410 is similar to theproportional flow control valve 210 as will be explained in more detailin the following with reference to FIG. 7. The second static seal fluidcontrol module 400 may also include conductors 440 a-c that are coupledto the power line 260. The conductors 440 a-c may also be coupled to thepump 220, the proportional flow control valve 410, and the integratedcontrol valve 420.

The integrated control valve 420 may be functionally similar to thede-superheat control valve 230 and the bypass control valve 240. Thatis, the integrated control valve 420 may combine the functions of thede-superheat control valve 230 and the bypass control valve 240. Theintegrated control valve 420 may include a valve core 422 that isslidably disposed in the module body 430. The integrated control valve420 may also be coupled to the module body 430 via a return spring 424that presses the valve core 422 to a released position. The releasedposition is shown in FIG. 6. The valve core 422 may be disposed in anintegrated chamber 434. The valve core 422 may include an integratedstem 422 a the both regulates fluid flow to the bypass valve 128 and tothe venturi 132. The integrated control valve 420 may also include astator 426 that is magnetically coupled to the valve core 422.

The module body 430 may include chambers that are in fluid communicationwith each other. For example, an impeller chamber 432 may be in fluidcommunication with the integrated chamber 434 via the conduits shown inFIG. 6. The module body 430 may also include inlets and outlets that arein fluid communication with each other. As shown, an inlet 432 a may bein fluid communication with a de-superheat port 428 a and a bypass pilotport 428 b via the integrated chamber 434. The inlet 432 a may also bein selective and proportional fluid communication with a evaporatorports 431 a,b. An exemplary fluid flow through the module body 430 isshown by the arrows at the inlet 432 a and the ports 428 a,b. Similar tothe first fluid control module 200, components in the module body 430may be immersed in the working fluid. The proportional flow controlvalve 410 may proportionally regulate the working fluid flow through thesecond static seal fluid control module 400 to the evaporator ports 431a,b as will be described in the following.

Simplified Schematic of a Static Seal Fluid Control Module

FIG. 7 shows a simplified schematic of a fluid control module schematic600 according to an embodiment. The fluid control module schematic 600may be a schematic representation of the first static seal fluid controlmodule 200 or second static seal fluid control module 400. The fluidcontrol module schematic 600 includes a proportional flow control valve610 that may be in fluid communication with a pump 620. The fluidcontrol module schematic 600 may also include a de-superheat controlvalve 630 and a bypass control valve 640 that may also be in fluidcommunication with the pump 620.

The proportional flow control valve 610 may be a simplifiedrepresentation of the proportional flow control valve 210 and theproportional flow control valve 410 described in the foregoing. Theproportional flow control valve 610 may proportionally regulate the flowfrom the pump 620 to the evaporator outlets 614, 616. The firstevaporator outlet 614 may be in fluid communication with, for example,the first evaporator 120. Similarly, the second evaporator outlet 616may be in fluid communication with the second evaporator 121.

The pump 620 may be a simplified representation of the pump 220described with reference to FIGS. 4 and 6. The pump 620 may receivefluid from the inlet 622. The inlet 622 may correspond with the inlet252 a and the inlet 432 a. The pump 620 may receive working fluid fromthe inlet 622 and supply it to the proportional control valve 610, thede-superheat control valve 630 and the bypass control valve 640 via avalve inlet 612, a de-superheat inlet 632, and a bypass control inlet642, respectively.

The de-superheat control valve 630 and the bypass control valve 640 mayregulate the flow of the working fluid to the de-superheat port 634 andthe bypass pilot port 644, respectively. For example, the de-superheatcontrol valve 630 may proportionally regulate the flow of the workingfluid to the bypass circuit 130 via the venturi 132. The bypass controlvalve 640 may selectively regulate the flow of the working fluid to thepilot valve actuator 139 on the bypass valve 128. The bypass controlvalve 640 may also regulate the flow of the working fluid to the pump220 via the pump return 646.

The foregoing describes the bypass valve 128 as being actuated by theworking fluid. Accordingly, the waste heat recovery systems 100 and 600may not have atmospheric dynamic seals. However, fluids other than theworking fluid may be used to actuator a bypass valve without anatmospheric dynamic seal as will be described in the following.

FIG. 8 shows another embodiment of a flow splitter 900. The spool 910 iscoupled to a return spring 920 similar to an earlier embodiment. Thespool is actuated with a brushless linear electric drive motor 930. Thismotor has a dry stator 932 and a wet rotor 934 that are separated by asealed can 936 that seals against the module body 940 as indicated at942. In this way, the can 936 serves as a membrane that contains theworking fluid so as to eliminate leakage of working fluid to atmosphere.

As indicated at 938, rotor 934 drives a double helix and ball bearingsto provide smooth travel of the spool and to allow the centralizingspring 920 to back drive the motor in reverse. The construction is allstainless steel with low friction, high wear coatings on the spool. Theunit is capable of engine mounting and has an IP69 automotive connector.The unit has porting to allow approximately a 9 mm diameter flow path.The profile of the spool can further be varied to accommodate specificdistribution requirements. Any appropriate means of moving the spool maybe employed.

FIG. 9A is a perspective view of another embodiment of a flow splitter1000, the cross-sectional view along AA being shown in FIG. 9B. Splitter1000 has a fluid inlet 1010, a first fluid outlet 1020 to a firstevaporator (not shown) located in the exhaust gas recirculation systemand a second fluid outlet 1030 to a second evaporator (not shown)located in the exhaust gas flow to the tailpipe. Sensors 1015 allow themeasurement of differential fluid pressures and the fluid pressure atthe fluid inlet, while sensor 1016 measures temperature.

Stem 1035 is configured to allow a greater maximum flow rate from inlet1010 to second fluid outlet 1030 than from inlet 1010 to first fluidoutlet 1020. This may be appropriate in situations where heat recoveryfrom the exhaust gas flow to the tailpipe is always going to be greaterthan the heat recovery from the exhaust gas recirculation flow.

Referring to FIGS. 9C and 9D, stem 1035 comprises, at one end, a firsttapered needle 1040 that moves in and out of a first seat 1041 at oneend of a first bore 1042 of diameter d1 between inlet 1010 and firstfluid outlet 1020. Spaced along the stem from the first needle is asecond tapered, frusto-conical valve member 1044 that moves relative toa second seat 1045 at one end of a second bore 1046 of diameter d2between the inlet 1010 and the second fluid outlet 1030. It will beappreciated that this second valve assembly is akin to that employed inthe embodiments of FIGS. 5,7 and 9. The relative dimensions of the firstand second valve assemblies comprising respective valve members, seatsand bores are chosen such that the maximum flow rate from inlet 1010 tosecond fluid outlet 1030 is greater than the maximum flow rate frominlet 1010 to first fluid outlet 1020. In the particular embodimentshown in FIG. 9D, d2 is greater than d1, with the maximum flow ratethrough d1 typically being around 20% of the flow rate through d2.

In other words, in a flow control valve having two or more distributionlegs, one leg is being modulated over a relatively small flow rangewhile the other is modulated over a much larger flow range, combiningthe low flow modulating characteristics of a small, tapered needle valvewhile also having the large flow characteristic of a larger bore spoolvalve.

As in previous embodiments, axial displacement of the stem results inone needle valve assembly opening and the other closing, the stem beingdisplaced axially by an actuator 1100 against a spring 1110 configuredto return the stem to a zero or default position, the position of thestem being sensed by a sensor comprising a magnet 1120 attached with theactuator and spring to the opposite end of the stem to the valveassemblies, the stem being supported between its ends by a spool portion1130 slideable in a housing bore 1140. Given the assymetric constructionoutlined above, the other end of the stem communicates with the fluidinlet by way of a passageway or balancing gallery 1150 so as to balancethe pressure forces acting on the stem.

Benefits of the Static Seal Fluid Control Modules

As described in the foregoing, the static seal fluid control modules200, 400 may selectively and proportionally regulate the working fluidflow through the waste heat recovery system 100 without atmosphericdynamic seals. For example, the static seal fluid control modules 200,400 may proportionally regulate the working fluid flow to theevaporators 120, 121. The static seal fluid control modules 200, 400 mayalso selectively regulate the working fluid flow to other parts of thewaste heat recovery system 100. For example, the static seal fluidcontrol modules 200, 400 may actuate the bypass valve 128 with fluidflow regulated by the bypass control valve 240 or the integrated controlvalve 420. In this example, the bypass control valve 240 or theintegrated control valve 420 may selectively supply the working fluid tothe pilot valve actuator 139 to actuate the bypass valve 128. The supplyof the working fluid to the pilot valve actuator 139 may also beproportionally regulated by the static seal fluid control modules 200,400. That is, the bypass valve 128 may be a proportional bypass valvethat proportionally regulates the flow between the bypass circuit 130and the expander 129.

The static seal fluid control modules 200, 400 may be in fluidcommunication with the vapor control module 103 via the fluid line 140.Accordingly, there may be working fluid on both sides of a dynamic sealin, for example, the bypass valve 128. That is, the bypass valve 128 mayemploy a dynamic seal. However, it may not be an atmospheric dynamicseal because working fluid is employed on both sides of the dynamic sealin the bypass valve 128. Additionally or alternatively, a membranebypass valve may be actuated with no atmospheric dynamic seals usingfluids other than the working fluid, such as pressurized air.

The embodiments described above provide a static seal fluid controlmodule 200, 400 and a waste heat recovery system 100 that can draw heatfrom two or more evaporators 120, 121. Accordingly, since no atmosphericdynamic seals are employed, the working fluid may not leak to atmospherevia dynamic seals. Combustible working fluid may therefore be employedin close proximity with the engine 101 without contacting hot portionsof the engine. For example, the working fluid may not leak onto theengine exhaust and thereby preventing undesired combustion of theworking fluid. The static seal fluid control modules 200, 400 may alsocontinue to flow working fluid through the waste heat recovery system100 when power is not provided to the static seal fluid control modules200, 400. Accordingly, the working fluid may not become over pressurizedthereby avoiding catastrophic failure of the module bodies 250, 430.

The detailed descriptions of the above embodiments are not exhaustivedescriptions of all embodiments contemplated by the inventors to bewithin the scope of the present description. Indeed, persons skilled inthe art will recognize that certain elements of the above-describedembodiments may variously be combined or eliminated to create furtherembodiments, and such further embodiments fall within the scope andteachings of the present description. It will also be apparent to thoseof ordinary skill in the art that the above-described embodiments may becombined in whole or in part to create additional embodiments within thescope and teachings of the present description.

Thus, although specific embodiments are described herein forillustrative purposes, various equivalent modifications are possiblewithin the scope of the present description, as those skilled in therelevant art will recognize. The teachings provided herein can beapplied to other waste heat recovery systems, and not just to theembodiments described above and shown in the accompanying figures.Accordingly, the scope of the embodiments described above should bedetermined from the following claims.

We claim:
 1. A fluid control module for a waste heat recovery system with a working fluid, comprising: a module body at least partially enclosing a pump and at least one valve, the module body having no dynamic seals to atmosphere.
 2. Fluid control module according to claim 1, wherein the pump and the at least one valve are adapted to be substantially immersed in the working fluid.
 3. Fluid control module according to claim 1, wherein the pump is adapted to be driven electrically.
 4. Fluid control module according to claim 1, wherein the pump comprises a moving element, in particular a rotor, that is adapted to be immersed in the working fluid.
 5. Fluid control module according to claim 1, wherein the pump comprises one or more bearings adapted to be immersed in the working fluid.
 6. Fluid control module according to claim 1, wherein the pump comprises a stator at least partially enclosed by the module body.
 7. Fluid control module according to claim 1, wherein the at least one valve comprises an electromagnetic actuator comprising a core, the core being adapted to be immersed in the working fluid.
 8. Fluid control module according to claim 1, wherein the at least one valve comprises a return spring adapted to place the at least one valve in a zero position state when the at least one valve is not actuated.
 9. Fluid control module according to claim 8, wherein the return spring is adapted to be immersed in the working fluid.
 10. Fluid control module according to claim 1, wherein the at least one valve includes a solenoid at least partially enclosed by the module body.
 11. Fluid control module according to claim 1, and comprising a first liquid control valve configured to selectively provide a fluid communication path between a fluid supply and a first evaporator port and a second liquid control valve adapted to selectively provide a fluid communication path between the fluid supply and a second evaporator port.
 12. Fluid control module according to claim 1, and comprising a proportional flow control valve that includes a proportional stem that is adapted to proportionally regulate a flow of the working fluid between a first evaporator port and a second evaporator port.
 13. Fluid control module according to claim 12, and comprising a return spring assembly adapted to return the proportional flow control valve to a zero position state.
 14. Fluid control module according to claim 1, wherein the at least one valve includes a stem adapted to regulate the working fluid flow to a pilot valve actuator on a bypass valve includes a stem adapted to regulate a flow of the working fluid to a bypass circuit to de-superheat the working fluid.
 15. Fluid control module according to claim 1, wherein the at least one valve includes a stem adapted to regulate the working fluid flow to a pilot valve actuator on a bypass valve and to a bypass circuit to de-superheat the working fluid.
 16. Fluid control module according to claim 1, and further comprising a power line that is coupled to the pump or the at least one valve wherein the power line is at least partially enclosed by the module body.
 17. Fluid control module according to claim 1, and further comprising a pump return that returns fluid from the at least one valve to the pump.
 18. A method of forming a fluid control module for a waste heat recovery system with a working fluid, comprising: forming and at least partially enclosing a pump and at least one valve with a module body without forming a dynamic seal to atmosphere.
 19. The method of forming the fluid control module of claim 18, further comprising the step of substantially immersing the pump and the at least one valve in the working fluid.
 20. The method of claim 18, further comprising forming and immersing a rotor in the working fluid.
 21. The method of claim 18, further comprising forming and immersing one or more bearings in the working fluid.
 22. The method of claim 18, further comprising forming and at least partially enclosing a stator in the module body.
 23. The method of claim 18, further comprising forming and immersing a core in the working fluid.
 24. The method of claim 18, further comprising forming and adapting a return spring to place the at least one valve in a zero position state when the at least one valve loses power.
 25. The method of claim 24 further comprising immersing the return spring in the working fluid.
 26. The method of claim 24 comprising at least partially enclosing a solenoid with the module body.
 27. The method of claim 18 comprises forming a proportional flow control valve.
 28. The method of claim 27 comprises forming and adapting a proportional stem to proportionally regulate a working fluid flow between a first evaporator port and a second evaporator port.
 29. The method of claim 27 further comprises forming and adapting a return spring assembly to return the proportional control valve to a zero position state.
 30. The method of claim 18 includes forming a stem adapted to regulate the working fluid flow to a pilot valve actuator on a bypass valve.
 31. The method of claim 18 includes forming a stem to regulate the working fluid flow to a bypass circuit to de-superheat the working fluid.
 32. The method of claim 18 includes forming a stem to regulate the working fluid flow to a pilot valve actuator on a bypass valve and to a vapor control module to de-superheat the working fluid.
 33. The method of forming the fluid control module of claim 18, further comprising forming and coupling a power line to the pump or the at least one valve and at least partially enclosing the power line with the module body.
 34. The method of forming the fluid control module of claim 18, further comprising forming a pump return that returns fluid from the one or more valves to the pump.
 35. Method of operating a fluid control module, comprising: receiving a working fluid at an inlet of the fluid control module; and providing the working fluid to one or more evaporators and to a pilot valve actuator on a bypass valve without containing the working fluid with an atmospheric dynamic seal.
 36. The method of operating a fluid control module of claim 35, further comprising providing the working fluid to a bypass circuit without containing the working fluid with the atmospheric dynamic seal.
 37. The method of claim 35, further comprising providing the working fluid to a venturi that forms a portion of the bypass circuit. 